Juniper MX routing engine redundancy

Juniper MX routers, except for the MX80, are capable of having two routing-engines (RE). In this article, I’ll configure an MX480 with some of the high-availability features offered by Junos. By using these features, you can decrease the downtime normally associated with a RE failure to an absolute minimum. Hardware... [Read More]
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MX RSVP firewall filter

Of course, you need to allow RSVP in the firewall filter you are using to protect the routing-engine. The book 'Juniper MX series' covers this very in-depth in chapter 4. It offers a very extensive guide or example on how you could go about building a proper firewall filter to... [Read More]
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Installing a bypass LSP into the forwarding table

After covering link-protection and node-link-protection here, I realized that I forgot one aspect. You can make Junos install the pre-signaled bypass LSP into the forwarding table. This is done by configuring a policy and by applying that policy under the [routing-options forwarding-table export ] stanza. A short example; [Read More]
Tags: juniper mpls rsvp

Fast reroute

Traffic sent across RSVP-signaled LSPs without any additional configuration is susceptible to quite some down-time when a node or a link in the network fails. In a previous article here, I made an LSP more robust by configuring a primary and a secondary LSP. Let’s further enhance the LSP by... [Read More]
Tags: juniper mpls rsvp

Primary and secondary LSPs for RSVP signaled LSPs

A failure somewhere in the network can cause for traffic traversing an RSVP-signaled LSP to drop. Several possibilities exist to reduce the impact a failure can have on RSVP-signaled LSPs. This article is about the creation of a secondary standby path in order to reduce downtime that is incurred upon... [Read More]
Tags: juniper mpls rsvp

Juniper QFX vlan-swapping

This is a quick and short article on how to perform vlan-swapping on a Juniper QFX5100. I was used to tunneling vlans in a QFX5100 by using the push-operation available through a vlan-map. With this in mind I was struggling to get vlan translation on the QFX5100 working. I was... [Read More]
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Basic RSVP signaled LSP on MX

This article is about the basic configuration on how to get an RSVP signaled MPLS LSP (label-switched path) working on a Juniper MX router. The focus will be on the minimum amount of configuration needed to create LSPs between the Tiberius and the Commodus router: [Read More]
Tags: juniper mpls rsvp

Juniper cos notes

These notes cover CoS on Juniper devices. The list of topics covered here correspond to the JNCIP-SP exam objectives. One objective is missing. I will cover the 'Given a scenario, demonstrate knowledge of how to configure and monitor CoS' somewhere else. [Read More]

Single-rate two-color policer on an EX.

Policing, also known as rate-limiting, can be used as an instrument to control how much traffic is allowed to flow in a certain direction. In Juniper, you can do this by using a policer as an action in a firewall filter. This article is about the configuration of two simple... [Read More]
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Juniper multihomed IP VPN location.

This article offers some insight into how you could decide to build a multihomed Layer 3 IP VPN or Layer 3 MPLS VPN. First I’ll go over the topology. After this, you will find the PE and CPE configuration. I’ll end with some verification and show commands. The topology: [Read More]
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QFX5100 802.1Q Tunneling (Q-in-Q)

A QFX5100 allows for dot1q-tunneling, or Q-in-Q. If you ever configured dot1q-tunneling on an EX-switch, this configuration differs a lot from what you may be used to. This article offers an attempt to clarify and explain the configuration of a dot1q-tunnel on a standalone QFX5100 without an enhanced feature license.... [Read More]
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Juniper MPLS VPN basics.

For a little while now, I have been wanting to do a Juniper IP VPN lab. I wanted to gather most of the basics into one post. In this post, I will elaborate on the different protocols and how they are configured. The complete configuration is posted at the bottom... [Read More]
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Juniper QFX and storm control

Recently, I deployed a VCF consisting of some QFX5100's and some EX4300's. I found that the default configuration did not really protect the network well enough and I thought I’d share it in this post. On the QFX, you’ll find that storm-control is enabled by default. The first thing you'll... [Read More]
Tags: juniper qfx

Juniper OSPF authentication options.

In Junos , OSPF authentication can come in one of three ways; none, simple or MD5. The default is to have no authentication. This means that the router will form a neighbor relationship with a neighboring router as long as the proper fields in the OSPF Hello’s are matching. Another... [Read More]
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Using apply-path in a prefix-list on Juniper.

Juniper's Junos offers a lot of flexibility as well as nifty little tricks. I recently ran into the situation in which 'apply-path' really came in handy. For a particular service, a different subnet was provisioned under the same interface over and over again. I wanted to advertise all of the... [Read More]
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